Impaired Endothelial And Microvascular Functions In Obese Patients: Analysis Of Blood Flow In The Femoral Artery During Passive Leg Movements

Microvascular and endothelial alterations are frequently associated with obesity and its cardiovascular and metabolic complications. Measurement of blood flow increase in the common femoral artery, by echo-doppler, during 1 minute of passive leg movements (PLM) of one leg, has recently emerged as a valuable non-invasive functional evaluation tool of endothelial/microvascular function. PURPOSE: (1) To identify the PLM test as a potential biomarker of endothelial/microvascular dysfunction in obese patients (OB). (2) To evaluate the effects on the biomarker deriving from a standard 3-wk in-hospital rehabilitation program (caloric restriction and moderate-intensity exercise). (3) To compare the PLM data with blood variables evaluating endothelial function and with systemic variables of oxidative function and exercise tolerance. METHODS: 15 male OB (age 18 ± 8 yr; body mass 121 ± 24 kg; body mass index 39.0 ± 7.5 kg·m−2) were tested before (PRE) and after (POST) the 3-wk multidisciplinary program. Eleven normal-weight, age-matched male volunteers (CTRL) underwent the PRE measurements. Participants performed on a cycle ergometer an incremental exercise to voluntary exhaustion (to determine peak pulmonary oxygen uptake (V̇O2peak) and gas exchange threshold (GET)) and the PLM test. Several blood biomarkers of endothelial dysfunction were also assessed. RESULTS: V̇O2peak and GET (normalized per body mass) were significantly lower (by 40%, p < 0.05) in OB vs. CTRL; in OB both variables were 5% higher (p < 0.05) in POST vs. PRE. Baseline blood flow was higher in OB vs. CTRL (p < 0.05); the difference was not significant after blood flow was normalized for the greater skeletal muscle mass in OB. Δpeak and the area under the blood flow vs. time curve (AUC) during PLM were lower in OB vs. CTRL (p < 0.05). The blood flow vs. time curve was upward-shifted following the 3-wk intervention, with no changes in Δpeak and AUC. Plasma nitrite concentration was significantly lower in OB vs. CTRL (p < 0.05). CONCLUSIONS: The blunted PLM-induced hyperemic response and the lower plasma nitrites in OB suggest a compromised endothelial and microvascular function. The 3-wk intervention positively improved systemic variables of oxidative metabolism and exercise tolerance, but only marginally affected endothelial/microvascular function. -Jagiellonian University Collegium Medicum, Project number N43/DBS/000221 -qLIFE Priority Research Area under the Excellence Initiative - Research University Programme at the Jagiellonian University, Project number 06/IDUB/2019/94 - Italian Ministry of Health – ricerca corrente (to Istituto Auxologi